Simrad ROBERTSON AP45 Marine Instruments User Manual


 
Robertson AP45 Autopilot
Start-Up procedure / Commissioning
Simrad Robertson AS
Egersund - Norway
Page 6-5
The COUNTER RUDDER serves two purposes, firstly to give a smooth transition
to the new heading after a major course change has been made, and secondly to
enable the autopilot to stabilise the vessel on a straight course.
The COUNTER RUDDER can be set to one of four values: OFF, LOW, MEDIUM
and HIGH. The best setting can only be found during a sea trial. Initial setting
should be LOW.
The value of the RUDDER LIMIT determines the maximum rudder movement in
degrees from midship position. The range is ±5° to ±55°. The adjustment is in
steps of 5 degrees, using the + or - button.
The RUDDER LIMIT should always be set approximately 5° less than the
maximum rudder angle to avoid damage on the steering gear.
Rudder limit also applies when hand-steering is made by FU-steering levers.
A deadband in the rudder control loop is necessary to filter out noise generated by
vibration. A narrow deadband may cause the rudder to hunt, a wide deadband will
create inaccurate steering.
The rudder deadband can be adjusted in steps of 0.1° from 0.2-1.6°. Adjust the
deadband when the vessel is tied dockside. Find the lowest possible value that will
prevent the rudder from hunting. Adjust by means of the + or - button. Counter
Rudder should be off during this test.
The AP45 Control Unit can be connected to navigation receivers with NMEA 0180
and/or NMEA 0183 output signal format. NMEA 0183 is the factory hardware set
up. If NMEA 0180 is required, contact your local dealer for details on how to
reconfigure the internal connections on Main PCB.
Refer to the nav. receiver manual and select the correct format by pressing the +
or - button.
In some occasions, e.g. at pair trawling, it is necessary to disengage the autotrim
function in WORK-mode. This is done by pressing the DECREASE (-) button.
To engage the autotrim function, press the INCREASE (+) button.
I I I I I
COUNT.RUDD.:LOW
Counter rudder
Rudder limit
I I I I
RUDD. LIM.: 15°
Rudder deadband
I I I I I
DEADBAND 1.0°
NMEA-format
NMEA0183-FORMAT
NMEA0180: -
WORK: AUTOTRIM
AUTOTRIM OFF?:-
Disengage of
autotrim-function in
WORK-mode